Device for drying moist material to be ground

ABSTRACT

A device for drying moist material to be ground, especially pit moist lime and clay in a housing which has its upper region provided with an inlet pipe and has its lower region provided with an outlet for the dried material, and which is furthermore provided with at least one funnel-shaped inwardly extending guiding surface, the inner chamber of said housing being adapted to be supplied with hot air. The device according to the present invention is characterized primarily in that the hot air is, through a twist ring adjacent the outlet in a helical manner, introduced into the interior of the housing and is withdrawn from the housing at the upper region thereof. The device according to the present invention is furthermore characterized in that the material to be ground is charged onto at least one rotating stray dish which distributes the material over the entire flow cross section with a twist which is opposite to the twist of the hot air flow.

United States Patent Porr [75] Inventor: Karl-Heinz Porr, Ostenfelde,

Germany [73] Assignee: Gebruder Hischmann Maschinenfabrik, Ennigerloh/Westf., Germany [22] Filed: Aug. 9, 1973 [21] Appl. No.: 387,105

[30] Foreign Application Priority Data Aug. 9, 1972 Germany 2239098 [52] US. Cl 34/173, 34/59, 34/168 [51] Int. Cl. F26b 19/00 [58] Field of Search 34/59, 57 E, 57 R, 165, 34/168, 171, 173, 174, 176, 179, 181; 259/9, DIG. 18

[56] References Cited UNITED STATES PATENTS 1,653,332 12/1927 Baechler.... 34/173 2,049,199 7/1936 Dornfeld.... 34/173 2,400,194 5/1946 Day et a1. 34/168 3,423,840 1/1969 Beeken 34/171 3,495,949 2/1970 Niedner et aL'... 34/57 E 3,566,582 3/1971 Yankura 34/57 E 3,728,239 4/1973 McDonald 314/57 R Mar. 18, 1975 FOREIGN PATENTS OR APPLICATIONS 1,070,512 6/1967 United Kingdom 34/57 E 728,033 10/1942 Germany 34/173 298,524 to gzg United Kingdom 34/173 Primary Examiner-Kenneth W. Sprague Assistant Examiner-James C. Yeung Attorney, Agent, or Firm-Walter Becker [57] ABSTRACT hot air is, through a twist ring adjacent the outlet in a helical manner, introduced into the interior of the housing and is withdrawn fromthe housing at the upper region thereof. The device according to the present invention is furthermore characterized in that the material to be ground is charged onto at least one rotating stray dish which distributes the material over the entire flow cross section with a twist which is opposite to the twist of the hot air flow.

6 Claims, 8 Drawing Figures DEVICE FOR DRYING MOIST MATERIAL TO BE GROUND The present invention relates to a device for drying moist material to be ground, especially pit moist limestone and clay, in a housing, the upper portion of which has an inlet pipe and the lower portion of which has an outlet for the ground material, said housing also being provided with a funnel-shaped inwardly extending guiding surface. The interior of said housing is adapted I to be supplied with hot air.

Starting with a drying device of the above mentioned type, it is an object of the present invention to provide a device for drying moist material to be ground which will assure a uniform distribution of the material to be ground over the entire flow cross section and will assure an as long as possible staying of the material to be ground within the housing to be supplied with hot air, in order to obtain a highly satisfactory drying.

These and other objects and advantages of the invention will appear more clearly from the following specification, in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a first embodiment of a drying device according to the present invention.

FIG. 2 represents a top view of the design according to FIG. 1.

FIG. 3 is a cross section through the lower portion of the device of FIG. 1, said section being taken along the line Ill-Ill of FIG. 1.

FIG. 4 is a longitudinal section through a second embodiment of a drying device according to the invention. FIG. 5 is a top view of the embodiment of FIG. 4.

FIG. 6 represents a longitudinal section through a third embodiment of the invention.

FIG. 7 is a top view of the device of FIG. 6.

FIG. 8 represents a cross section through the upper portion of the device according to FIG. 6, said section being taken along the line VIII-VIII of FIG. 6.

The device according to the present invention is characterized primarily in that the hot air is introduced along a helical path into the interior of the housing through a twist ring arranged at the outlet and is withdrawn from the upper range of the housing, said device furthermore being characterized in that the material to be ground is charged onto a rotating stray dish which distributes the material to be ground over the entire cross-sectional surface with a twist which is opposite to the twist of the hot air flow.

According to a further feature of the invention, the

housing is widening below the funnel-shaped drawn-in guiding surface and is subsequently increasing in diameter toward the outlet, while in this region a stationary double cone is provided as guiding body. In this way, a particularly good contact of the material predried in the upper region of the housing with the fresh hot air will be obtained.

According to a further development of the invention, a plurality of funnel-shaped narrowing guiding surfaces and at least two stray dishes may be arranged one below the other and respectively within the region of the maximum diameter. According to the invention it is possible to drive the stray dishes independently of each other and at different speeds.

In view of the above features, there will be obtained not only a greater staying period of the material to be ground in the housing of the drying device, but in view of the arrangement of two stray dishes operable independently of each other, there will also be assured a good adaptability of the distribution of the material to be ground to the properties of the respective material to be dried.

In order to realize a uniform charging of the material to be ground onto the upper stray dish, the charging of the material to be ground may be effected through the hollow shaft of the upper stray dish. The hollow shaft is preferably provided with a supply pipe for supplying the material to be ground. Inasmuch as the material to be ground after being charged into the housing still contains a high proportion of moisture, the diameter of the housing in the upper portion may be shorter than in the intermediate part in order to compensate for the differences in the specific weight.

According to a further feature of the invention, adjustable impact plates may be arranged on the funnelshaped guiding surfaces, said impact plates being adapted to generate an intensive turbulence inthe interior of the housing. If the stray dishes in addition to distributing the material are intended simultaneously to bring about a certain crushing of the material, the stray dishes may, according to the invention, comprise individual beater arms.

With regard to the supply of air, it is suggested according to the invention to arrange the twist ring within a spiral-shaped air supply housing and to provide said ring with adjustable guiding blades so that the air which by an air generator not forming part of the drying device is supplied in hot condition to the housing with the necessary twist. The outlet of the hot air in the upper portion of the housing is expediently effected in the direction of the twist to which end there are provided air outlet housings designed accordingly.

The first embodiment of the device for drying moist material to be ground is illustrated in FIGS. 1 3 and comprises primarily a cylindrical housing 1 provided with funnel-shaped inwardly extending guiding surfaces 2. The supply of the material to be ground is effected through a stationary inlet pipe 3, whereas the outlet of the ground material is effected through a discharge 4. The material to be ground is charged onto a first stray dish 5 which together with the second stray dish 6 is connected to a shaft 8. Shaft 8 is driven through a belt transmission by a motor 7. Both stray dishes 5 and 6 are arranged within the region of the greatest diameter of housing 1, and more specifically, above a funnelshaped narrowing guiding surface 2. In the lower portion of housing 1 which narrows toward the outlet 4 in a likewise funnel-shaped manner there is arranged a stationary double cone 9.

While the material to be ground and charged onto the upper stray dish 5 is, by the latter, distributedover the flow cross section while simultaneously being subjected to the effect of centrifugal force and a circumferential component, and stepwise moves downwardly over the guiding surfaces 2, the subsequent stray dish 6, the subsequent guiding surface 2 and the double cone 9, hot air is in countercurrent flow and with an oppositely directed twist guided from below in the direction upwardly through the housing 1. To this end, above the outlet 4 there is provided a spiral-shaped air guiding housing 10 which is provided with a twist ring 11.

In conformity with the arrows in FIG. 1 shown in dash line hot air passes in FIG. 1 in upward direction in housing 1 and leaves said housing through an air outlet housing 12. These air outlet housings 12 are arranged in the direction of flow of the air being discharged in order to take advantage of the twist flow.

The second embodiment according to FIGS. 4 and 5, differs from the preceding above mentioned embodiment merely in that the supply of material to be ground is effected centrally through the hollow shaft 8. To this end, within shaft 8 there is provided a supply pipe 13 for supplying the material. The air employed for drying the material to be ground, leaves according to the second embodiment of the invention, the housing 1 in axial direction through two air exit connections 14. Finally, the housing is in the upper region provided with a shorter diameter than is the case in the intermediate range.

According to the third embodiment of the invention, as illustrated in FIGS. 6 8 which primarily corresponds to the first embodiment of the invention, the stray dishes 5 and 6 are formed by individual beating arms 5a, 6a so that the stray dishes 5 and 6 exert a certain diminishing effect upon the material to be ground.

The beater arms 5a, 6a are arranged on separate shafts 8a, 8b respectively. Each shaft 8a, 8b is operable independently of the other one so that it will be possible to employ not only different speeds but also different directions of rotation.

In contradistinction to the above mentioned two embodiments, according to the third embodiment of the invention, two additional impact plates are arranged on the funnel-shaped guiding surfaces 2. The two additional impact plates 15 are adjustable as to height and can be rotated about their connecting axis. In view of these impact plates 15, an additional turbulence is created between the material to be ground and the hot air.

It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings, but also comprises any modifications within the scope of the appended claims.

What I claim is:

l. A device for drying moist material to be ground, especially pit moist lime and clay, which includes a housing having an upper portion with inlet means for conveying material to be dried into the interior of said housing and also having a lower portion with central outlet means for discharging dried material from said housing, twist ring means including a helical guiding path and arranged adjacent said outlet means for introducing hot air into said housing in countercurrent flow to the flow of material to be dried, rotatable stray dish means arranged within said housing for receiving and distributing the material to be dried with a twist opposite to the twist of the hot air flow, said rotatable stray dish means including means for driving connection with a motor, hot air discharge means arranged at the upper portion of said housing for discharging hot air from said housing, and funnel-shaped downwardly tapering guiding surface means arranged in the interior of said housing for guiding the material to be dried from the upper portion of said housing through the latter and for conveying hot air in countercurrent flow to the flow of material to be dried to said hot air discharge means, said housing below every said funnel-shaped guiding surface means having configuration which widens again to largest diameter of said housing and subsequently narrows again toward said outlet means, a double cone arranged in a range of the lowermost guiding surface means within said widening and narrowing guiding surface means in spaced relation thereto to define therewith a path for hot air and for dried material, said funnel-shaped guiding surface means including a plurality of serially arranged downwardly tapering conical guiding surfaces and at least two stray dishes arranged in vertical direction one below the other and located within the region of the largest diameter of said housing, and at least one motor driving means driving said stray dishes upon the uppermost of which material to be dried is given off, said twist ring means including one portion thereof arranged above said outlet means for entry of hot air which streams through said housing from below to the top with a twist counter to twist of said stray dishes through which material is directed.

2. A device according to claim 1, in which the lower portion of said housing is provided with a spiral-shaped air supply housing, and in which said twist ring means is arranged within said air supply housing and is provided with adjustable guiding blades.

3. A device according to claim 1, in which said hot air discharge means includes a spiral-shaped discharge housing extending in the direction of the twist to be imparted upon the hot air.

4. A device according to claim 1, which includes motor driving means respectively connected to each of said stray dishes for driving the same independently of each other and selectively at different speeds.

5. A device according to claim 1, in which said stray dish means include individual beater arms.

6. A device according to claim 1, which includes impact plates adjustably arranged on said funnel-shaped guiding surface means.

. =l l= =l 

1. A device for drying moist material to be ground, especially pit moist lime and clay, which includes a housing having an upper portion with inlet means for conveying material to be dried into the interior of said housing and also having a lower portion with central outlet means for discharging dried material from said housing, twist ring means including a helical guiding path and arranged adjacent said outlet means for introducing hot air into said housing in countercurrent flow to the flow of material to be dried, rotatable stray dish means arranged within said housing for receiving and distributing the material to be dried with a twist opposite to the twist of the hot air flow, said rotatable stray dish means including means for driving connection with a motor, hot air discharge means arranged at the upper portion of said housing for discharging hot air from said housing, and funnel-shaped downwardly tapering guiding surface means arranged in the interior of said housing for guiding the material to be dried from the upper portion of said housing through the latter and for conveying hot air in countercurrent flow to the flow of material to be dried to said hot air discharge means, said housing below every said funnel-shaped guiding surface means having configuration which widens again to largest diameter of said housing and subsEquently narrows again toward said outlet means, a double cone arranged in a range of the lowermost guiding surface means within said widening and narrowing guiding surface means in spaced relation thereto to define therewith a path for hot air and for dried material, said funnel-shaped guiding surface means including a plurality of serially arranged downwardly tapering conical guiding surfaces and at least two stray dishes arranged in vertical direction one below the other and located within the region of the largest diameter of said housing, and at least one motor driving means driving said stray dishes upon the uppermost of which material to be dried is given off, said twist ring means including one portion thereof arranged above said outlet means for entry of hot air which streams through said housing from below to the top with a twist counter to twist of said stray dishes through which material is directed.
 2. A device according to claim 1, in which the lower portion of said housing is provided with a spiral-shaped air supply housing, and in which said twist ring means is arranged within said air supply housing and is provided with adjustable guiding blades.
 3. A device according to claim 1, in which said hot air discharge means includes a spiral-shaped discharge housing extending in the direction of the twist to be imparted upon the hot air.
 4. A device according to claim 1, which includes motor driving means respectively connected to each of said stray dishes for driving the same independently of each other and selectively at different speeds.
 5. A device according to claim 1, in which said stray dish means include individual beater arms.
 6. A device according to claim 1, which includes impact plates adjustably arranged on said funnel-shaped guiding surface means. 